Commonly owned U.S. Patent application Ser. No. 184,240, filed concurrently with said Ser. No. 184,286, discloses a flexible sheet material having a patterned relief surface of high quality and definition formed on one side thereof. This relief patterned sheet material is of a composite construction and comprises a base film having a layer of a cured thermosetting polymer overlying one surface of the base film and wherein the relief pattern is formed in the thermosetting polymer layer. As noted in the aforementioned co-pending application, this type of sheet material has significant advantages over the relief patterned sheet presently available.